Cap device and liquid ejection apparatus

Abstract

A cap device includes a cap, an accommodation member, and a cover. The cap covers a nozzle surface of a liquid ejection head. The accommodation member is accommodated in the cap and is fixed to the cap. The accommodation member has a conductivity and receives a voltage that generates a potential difference between the liquid ejection head and the accommodation member. The accommodation member includes a first portion and a second portion connected with each other. The cover covers the second portion of the accommodation member, and has a surface that is co-planar with a surface of the first portion. The cover has a conductivity and receives a voltage that generates a potential difference between the liquid ejection head and the cover.

What is claimed is: 
     
       1. A cap device comprising:
 a cap configured to cover a nozzle surface of a liquid ejection head, the nozzle surface including a plurality of nozzles each ejecting a droplet of liquid therefrom; 
 an accommodation member that is accommodated in the cap, the accommodation member having a conductivity and configured to receive a voltage that generates a potential difference between the liquid ejection head and the accommodation member, the accommodation member including a first portion and a second portion connected with each other, the accommodation member being fixed to the cap; and 
 a cover configured to cover the second portion of the accommodation member, the cover having a conductivity and configured to receive a voltage that generates a potential difference between the liquid ejection head and the cover, 
 wherein the first portion has a surface configured to face the nozzle surface, and 
 wherein the cover has a surface configured to face the nozzle surface. 
 
     
     
       2. The cap device according to  claim 1 ,
 wherein the cap device further comprises a protrusion, the protrusion passing through the accommodation member, and the protrusion extending toward the nozzle surface when the surface of the first portion in the accommodation member faces the nozzle surface, the protrusion fixing the accommodation member to the cap, and 
 wherein the cover is configured to cover the protrusion. 
 
     
     
       3. The cap device according to  claim 1 ,
 wherein the accommodation member has a concave portion, 
 wherein a bottom of the concave portion corresponds to a surface of the accommodation member, and 
 wherein the cover is fit for the concave portion. 
 
     
     
       4. The cap device according to  claim 3 ,
 wherein a gap is located between the surface of the first portion in the accommodation member and the surface of the cover. 
 
     
     
       5. The cap device according to  claim 4 ,
 wherein the gap has a width in a first direction and extends in a second direction along the bottom of the concave portion, the second direction being orthogonal to the first direction, and 
 wherein a width of the gap in the first direction is greater than a distance between a pair of the nozzles in the plurality of nozzles. 
 
     
     
       6. The cap device according to  claim 4 ,
 wherein at least one of the surface of the first portion in the accommodation member and the surface of the cover includes an inclined surface, and 
 the inclined surface is angled outwardly. 
 
     
     
       7. The cap device according to  claim 6 ,
 wherein the surface of the first portion in the accommodation member includes the inclined surface and the surface of the cover includes the inclined surface. 
 
     
     
       8. The cap device according to  claim 4 ,
 wherein the accommodation member includes a cavity extending in a first direction, the cavity being separated from the concave portion by the cover, 
 wherein the cover includes a hook configured to separate the cavity from the concave portion, 
 wherein the hook and the gap overlap in a vertical direction, and 
 wherein the hook is configured to define a bottom of the gap in the vertical direction. 
 
     
     
       9. The cap device according to  claim 8 ,
 wherein the cover having a first width extending in the first direction and a second width extending in a second direction, the second direction being orthogonal to the first direction, and the second width being less than the first width, and 
 wherein the hook is disposed at an end of the cover in the first direction. 
 
     
     
       10. The cap device according to  claim 8 ,
 wherein the cap includes a discharging outlet at the bottom of the cap, the discharging outlet being for discharging ink in the cap, and 
 wherein the hook and the discharging outlet do not overlap in the vertical direction. 
 
     
     
       11. The cap device according to  claim 1 ,
 wherein the accommodation member includes a resin having a conductivity, 
 wherein the cap includes a discharging outlet at a bottom of the cap, the discharging outlet being for discharging ink in the cap, and 
 wherein the accommodation member covers the discharging outlet. 
 
     
     
       12. The cap device according to  claim 1 ,
 wherein each of the accommodation member and the cover is electrically connected to a voltage application member that applies a voltage thereto. 
 
     
     
       13. A liquid ejection apparatus comprising:
 a cap; 
 a liquid ejection head configured to move to a position where the liquid ejection head faces the cap, the liquid ejection head having a nozzle surface, the nozzle surface having a plurality of nozzles each ejecting a droplet of liquid therefrom; 
 an accommodation member that is accommodated in the cap, the accommodation member having a first surface and a second surface, the first surface facing the nozzle surface, the second surface facing the nozzle surface and being farther from the nozzle surface than the first surface, the accommodation member having a conductivity; 
 a protrusion protruding from the second surface of the accommodation member, the protrusion passing through the cap and the accommodation member, the protrusion fixing the accommodation member to the cap; 
 a cover configured to cover the protrusion, the cover having a surface, which is configured to face the nozzle surface, the cover having a conductivity; 
 a signal output member configured to output a signal indicating a potential difference between the liquid ejection head and at least one of the accommodation member and the cover; and 
 a controller configured to:
 cause a droplet to be ejected from each of the plurality of nozzles toward the accommodation member and the cover; 
 receive the signal from the signal output member; and 
 determine an ejecting condition of the plurality of nozzles in accordance with the received signal. 
 
 
     
     
       14. The liquid ejection apparatus according to  claim 13 ,
 wherein the accommodation member has a concave portion, a bottom of the concave portion corresponds to the second surface of the accommodation member, and 
 wherein the cover is fit for the concave portion. 
 
     
     
       15. The liquid ejection apparatus according to  claim 13 ,
 wherein a gap is located between the first surface of the accommodation member and the surface of the cover, 
 wherein the controller determines that:
 the ejecting condition does not have an error in a case where the potential difference is greater than a threshold value, and 
 the ejecting condition has an error in a case where the potential difference is not more than the threshold value, and 
 
 wherein the threshold value for a particular nozzle that ejects a droplet toward the gap is less than the threshold value for a nozzle other than the particular nozzle. 
 
     
     
       16. The liquid ejection apparatus according to  claim 13 ,
 wherein a gap is located between the first surface of the accommodation member and the surface of the cover, 
 wherein the controller determines that:
 the ejecting condition does not have an error in a case where the potential difference is less than a threshold value, and 
 the ejecting condition has an error in a case where the potential difference is not less than the threshold value, and 
 
 wherein the threshold value for a particular nozzle that ejects a droplet toward the gap is greater than the threshold value for a nozzle other than the particular nozzle. 
 
     
     
       17. A cap device comprising:
 a cap configured to cover a nozzle surface of a liquid ejection head, the nozzle surface including a plurality of nozzles each ejecting a droplet of liquid therefrom; 
 an accommodation member that is accommodated in the cap, the accommodation member having a conductivity and configured to receive a voltage that generates a potential difference between the liquid ejection head and the accommodation member; 
 a protrusion protruding from a surface of the accommodation member, the protrusion having a non-conductivity, the protrusion passing through the cap and the accommodation member, the protrusion fixing the accommodation member to the cap; and 
 a cover configured to cover the protrusion, the cover having a conductivity and configured to receive a voltage that generates a potential difference between the liquid ejection head and the cover.